/*
 *    Copyright 2009-2012 the original author or authors.
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */
package org.apache.ibatis.reflection.property;

import java.util.Locale;

import org.apache.ibatis.annotations.HasRead;
import org.apache.ibatis.reflection.ReflectionException;

/**
 * @author Clinton Begin
 */

/**
 * 属性命名器
 * <p>
 * 这个类提供了几个用来判断属性特征和从方面名称中获取属性名称的函数，
 * 我们首先来看判断一个方法名称是否是操作的一个属性的方法，
 * 如注释中所讲的返回true并一定就是一个属性。
 */
@HasRead
public final class PropertyNamer {

    private PropertyNamer() {
        // Prevent Instantiation of Static Class
    }

    //方法转为属性
    public static String methodToProperty(String name) {
        //去掉get|set|is
        if (name.startsWith("is")) {
            name = name.substring(2);
        } else if (name.startsWith("get") || name.startsWith("set")) {
            name = name.substring(3);
        } else {
            throw new ReflectionException("Error parsing property name '" + name + "'.  Didn't start with 'is', 'get' or 'set'.");
        }

        //如果只有1个字母-->转为小写
        //如果大于1个字母，第二个字母非大写-->转为小写
        //String uRL -->String getuRL() {
        if (name.length() == 1 || (name.length() > 1 && !Character.isUpperCase(name.charAt(1)))) {
            name = name.substring(0, 1).toLowerCase(Locale.ENGLISH) + name.substring(1);
        }

        return name;
    }


    /**
     * 根据传入的参数判断这个参数是不是应包含属性
     * 判断的依据是这个参数是不是以get|set|is开头的。但这个函数的判断依据是比较简单的，这一个必然条件。
     * 也就是说如果这个函数返回false，则这个参数肯定部包含属性；反之，如果这个函数返回true,则只能说明这个参数可能包含属性
     */
    public static boolean isProperty(String name) {
        //必须以get|set|is开头
        return name.startsWith("get") || name.startsWith("set") || name.startsWith("is");
    }

    //是否是getter
    public static boolean isGetter(String name) {
        return name.startsWith("get") || name.startsWith("is");
    }

    //是否是setter
    public static boolean isSetter(String name) {
        return name.startsWith("set");
    }

}
